EVolution , Bio

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EVolution , Bio
2012-03-31 03:00:58

evolution power point
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  1. Evolution
    accumulation of intended changes within populations over time
  2. Natural selection (2)
    acts to remove the negative traits from a population until it disappears.

    -elimination of the least fit, affects phenotype
  3. Darwin's voyage
    Galapagos islands to South American land
  4. 4 postulates of Darwin
    - overproduction

    -population growth is limited


    -differential reproductive success
  5. (4 darwin postulates) Over production
    each species has ability to produce copious offsrping, yet populations stay constant
  6. (4 darwin postulates) Population growth is limited
    resources are limited

    -exists a struggle when individuals/populations compete for resources
  7. (4 darwin postulates) VAriation
    individuals within a population exhibit inherited variations
  8. (4 darwin postulates) Differential reproductive success
    individuals that posses the most favorable traits to survive are more likely to pass them to their offspring
  9. Discovery of Charles Lyell
    earth changed slowly over time due to geological processes
  10. Discovery of Thomas Malthis
    population growth is not always desirable
  11. Discovery of Georges Cuvier
    -documented fossil discoveries

    -shared extinction occurred
  12. Discovery of Jean Baphite Lamarck
    suggested that living species change over time
  13. 3 types of speciation


  14. (types of speciation) Allopatric
    populations of a species became geographically isolated

    -over time populations will become genetically different in response to their habitats, gene flow ceases
  15. (types of speciation) Sympatric
    populations of a species that share same habitat become reproductively isolated from each other

    -can happen by just finding a new niche.
  16. (types of speciation) Parapatric
    speciations when populations are seperated by an extreme change in habitat

    -makes them interbreed at different times
  17. 5 agents that change allele frequencies

    -gene flow

    -genetic drift

    -nonrandom mating

    -natural selection
  18. (5 agents) Mutations
    alteration in an organisms DNA.

    -no harmful effect

    -beneficial or adoptive mutations are indispensible to evolution
  19. (5 agents) gene flow
    movement of alleles from one population to another

    -occurs when individuals move between populations

    -or when populations species joins another
  20. (5 agents) Genetic drift
    chance alteration of gene frequencies

    -strongly affects small population

    ex) bottle neck and founder effect
  21. (5 agents) non-random mating
    -occurs when one member is not equally to mate with any other member in population

    -includes sexual selection
  22. (5 agents) Natural selection
    some individuals will be better at surviving in the environment than other thus passing on their traits.
  23. (genetic drift) Bottle neck
    caused by changing environment resulting in a small population of survivors

    -as populations rebuilds, new gene pool may develop differing from old.
  24. (genetic drift) Founder effect
    caused by small groups of populations called colonies, formed due to isolation.
  25. Hardy-Weinberg genetic equilibrium
    if an individual with a certain gene is as reproductively fit as others in population than the gene will persist with some frequency from generation to generation
  26. 3 types of selection


  27. (selection) Stabilizing
    -infant will way low or very high birth weights have a higher rate of mortality

    -diversity decreased. intermediates favored
  28. (selection) Directional
    changes in environmental conditions focuses on one extreme

    -favors one extreme
  29. (selection) Disruptive (4)
    environmental conditions favors each extreme

    -genetic diversity

    -may lead to development of new species

    favors both extremes over intermediate trait
  30. Prezygotic barriers (6)


    • -temporal
    • ----------------

    • -behavioral
    • - mechanical
    • -gamete
  31. (prezygote barriers) Geographical 1. ext
    individuals of 2 populations cannot interbreed if they live in different places
  32. (prezygote barriers) ecological 2. ext
    even if they live in same place, they cannot mate if thhey dont have in contact
  33. (prezygote barriers) Temporal 3. ext
    even if they come in contact, they cant breed if they breed at different times
  34. (prezygote barriers) Behavioral 4. int
    even if they breed same time they wont mate if they are not attracted to one anohter.
  35. (prezygote barriers) Mechanical 5. int
    even if they are attracted to one another they cannot mate if they arent physically compatible
  36. (prezygote barriers) Gamte 6. int
    even if they are physically compatible an embryo will not form if the egg and sperm do not fuse properly
  37. Postzygotic barriers (3)
    -Hybrid inviability

    - hybrid sterility

    -hybrid breakdown
  38. (postzygotic barriers) Hybrid inviability
    occurs when zygote dies before reaching maturity
  39. (postzygotic barriers) Hyrbid sterility
    occurs when unequal #'s of chromosomes causes breakdown during meiosis and not allowing hybrid to product viable egg or sperm
  40. (postzygotic barriers) Hybrid breakdown
    F2, F3 generation is defective and unable to reproduce
  41. contributions to evolution: Comparative anatomy (2)
    -homologous textures: derive from same structure in common ancestor

    -vestigial structures: remnants of structure
  42. contributions to evolution: Development biology
    - Universally of genetic code

    -cell theory: cells come from other cells